Part of the show Skin Diseases and Skin Cancer
Just when we were all coming round to the idea of ditching our long-standing relationship with the video recorder in favour of a state of the art DVD player, researchers at Imperial College, London, announced this week that they have come up with a new design for a digital disc which, despite being the same size as a traditional CD or DVD, will be able to store up to 200 times more information - enough, in fact, to hold every episode of the Simpsons ever made, or the complete Lord of the Rings trilogy, 13 times over. That's about 470 hours of film. Peter Torok and his team, who have come up with the new disc-design, have christened their invention MODS (no, nothing to do with violent 1960's yob factions, it actually stands for Multiplex Optical Data Storage. Under the microscope, CDs and DVD's consist of a long groove or track, a bit like a race course, which spirals out from the centre of the disc towards the edge. If you unwound this groove it would stretch about three and a half miles. At regular points along the track - think of them as the furlongs on our race track analogy, the disc contains either a small pit, or the surface is left flat. The sequence of these pits and flat areas is used to digitally encode the data on the disc. The new MODS system takes the design a step further. The pits are asymmetrically shaped and contain a sunken step precisely positioned at one of 332 different angles. The angle of the step in the pit can therefore encode the information meaning that each pit can carry 10 times more information than in a traditional CD or DVD. The new system will be designed to be reverse-compatible with existing technologies like CDs and DVDs. Critically it will also enable developers to make storage devices much smaller than they are today.